Automatic gun



9 6 A. m L L A m me am MT Am w AU .A F K Nov. 8, 1 927.

-16 Sheets-Sheet J.

// IN VENTORS K .F. AzmMso/v H. J. JTAMB/IUGH A TTQRNEY Filed Nov. 1, 1924 Nov. 8, I92 7.

K. F. ADAMSON ET ALv AUTOMATIC GUN Filed NOV. l, 1924 16 Sheets-Sheet 2 I N VEN TORS A. 5470 0160 T TORNE Y .J. Srnnsnuaw Nov. 8, 1927. 1,8,469

K. F. ADAMSON ET AL AUTOMATIC GUN Filed Nov. 1

6 Sheets-Sheet 3 IN VEN TORS K. f. A DAMSON h. J. STAN/BA 00/4 A TTORNE Y Nov. 8, E92 7.

K. F. ADAMSON ET AL,

AUTOMATIC GUN 16 Sheets-Sheet IN VEN TORS v /(./4DAM60N /7.J. TAMBAl/GH 3 v W m Z A TTORNE Y Filed NOV. 1, 1924 Nov. 8, 1927. 1,648,469-

K. F..'ADAM$ON ET AL I AUTOMATIC GUN Filed Nov. 1, 1924 16 Sheets-Sheet 5 INVENTORS K F. ADA/480A! y H. J. STAMBAUGH MVZWZ ATTORNEY Nov. 8, 1927. v 1,648,469

K. F. ADAMSON ET AL.

AUTOMATI C GUN Filed Nov. 1, 1924 16 Sheets-Sheet 6 v @Q mlwm 16 Sheets-Sheet 7 E EM? AUTOMATICGUN K. F. ADAMSON ET AL Filed Nov. 1, 1924 Nov. 8, 192 7.

H s 6 W W/w Twa 5N m QM vmm VT W 16 Sheets-Sheet 9 I llll ll AUTOMATIC GUN Filed Nov. 1, 1924 K. F. ADAMSON ET AL Nov. 8, 1927.

@ I INVENTORS' I K. F. ADA/v60 H d. 87'AMB/N/6H ATTORNEY Nov. 8, 1927.

K. F. ADAMSON ET AL auwotmxc GUN Filed Nov.

16 Sheets-Sheet 11 INVENTORS K. E. AnAMso/v H. J STIMBAUGH ATTORNEY Nov. 8, 1927.

K. F. ADAMSON ET AL.

AUTOMATIC GUN 2 l t av e .h 4 s t e e a 6 1 Filed Nov. 1. 1924 IN VEN TORS l1. EADAMsO/ H. J. 8 7411154110 @M A TTORNE V II I I Nov. 8, 1921.

K. F. ADAMSON' ET AL AUTOMATIC GUN Filed Nov; 1, 1924 16 Sheets-Sheet; 13

AUTOMATIC GUN Filed Nov, 1; 1924 l6 Sheetsl4 ATTORNEy Nov. 8, 1927 K. F. ADAMSON ET AL,

AUTOMATIC GUN l6 Sheets-Sheet 1 314mm cza- Patented Nov. 8, 1927.

UNITED STATES PATET oFFicE.

KEITH r. ADAMSON, or FORT BRAGG, NORTH CA1.?.O2[. I1\TA, A'ND HENRY J. s'rAMBAUGH,

or TROY, NEW YORK.

AUTOMATIC GUN.

Application filedNovember 1, 1924. Serial No. 747,764.

(GRANTED UNDER THE ACT 0]? MARCH 3,1883; 22 STAT. L. 625.)

The invention described herein 'may be used by the Government, or any of its 0thcers or employees in prosecution of work for the, Government,-or by any other person in the United States, without payment to us of any royalty thereon, in accordance with the act of March 3, 1883.

The subject of this invention is an automatic gun, designed for shells of 37 mm. caliber though not restricted thereto.

The purpose of the present invention is to provide an automatic gun of the sliding breech block type, in which extraction takes place during an early stage of recoil and ejecting during a later stage. The rammer is energized during recoil and swung to ramming position, which movement releases the rammer to ram a cartridge directly from the magazine into the cartridge chamber while the gun is still in full recoil, the rammer riding a short distance with the gun in counter-recoil to hold the loaded round in place until the breech block starts to close. The magazine is given partial rotation during counter-recoil to successively bring each round into position to be loaded. A disc for indicating the number of rounds fired from a magazine is associated with the mechanism for actuating the magazine and is rotated in unison therewith. Means controlled by the aforesaid disc prevents firing of the,

last round from the magazine after said round is fed into the gun so that the gun is ready to go into operation when the magazine is replaced or replenished.

To these and other ends, our invention consists in the construction, arrangement, and combination of elements, described hereinafter and pointed out in the claims forming a part of this specification.

A practical embodiment of our invention is illustrated in the accompanying drawings,

in which,

Figs. 1 and l are plan views partly in section of the gun in battery;

Fi s. 2 and 2 are similar views of the gun 1n the full recoil position;

Figs. 8 and 3 are views in left side elevation, partly in section, of the gun in batterv;

Figs. 4 and 4 are similar views of the gun in full recoil;

Figs. 5 and 5 are views in right side eleyation, partly in section, of the gun in bat- Figs. 6 and 6 are similar views of the gun in full recoil;

Fig. 7 is a sectional view taken on the line 7-7 of Fig. 1*;

Fig. 8 is a sectional view takenon the line. 88 of Fig. 1;

Fig. 9 is a rear end view of the gun in battery, partly in section to show the rollers of the rammer and the breech block;

F 1g. 10 is a rear end view partly in sec- U011 of the gun in full recoil;

F 1g. 11 is a detailed sectional view of the firing mechanism;

Fig. 12 is a detailed sectional view of the firing cam plunger;

Fig. 134s a fragmentary sectional view of the mechanism for preventing firing'of the last round;

Fig. 14: is a sectional view on line 14.14 of Fig. 13;

Fig. 15 is a detailed view of the leaf spring;

Fig. 16 is a plan view of the rear end of the trigger rod;

Fig. 17 is a sectional viewon the line 1717 of Fig. 16;

Fig. 18 is a plan View of the rear end of the firing-rod;

Fig. 19 is a sectional view on the line 1919 of Fig. 18;

Fig. 20 is a rear elevation partly in-section of the trigger and crank; and

Fig. 21 is a view in side elevation thereof.

Referring to the drawings by numerals of reference:

In carrying out our invention, we provide a'cradle 1 (see Fig. 7) having a top plate 2 formed with guide ways 3 for reciprocally mgunting a jacketdwhich carries a gun barre 5.

Secured to the forwardend of the cradle is a bridge support 6 (see Figs. 1 to 6 and Fig. 7 for stationarily mounting a cylinder returning the gun'to battery.

The breech end of the barrel is formed with a transverse passage 10? in which is slidably mounted a breech block 10 movable in opening from left to right and shown in the closed and open positions respectively, in Figures 8 and 9. For the purpose of operating the breech block and imparting to it a more rapid rectilinear movement than that of the part furnishing the moving force a pinion 11 is provided which is in mesh with a rack 12 on the breech block and also with a fixed rack 13, located in the rear of the passage 10. The pinion (see Fig 9) 11 is mounted on a pin 14, passingthrou'gh a hollow post 15 which is fixed to atransverse slide 16 in the breech ring. The lower end of the post carries a. roller 17 retained in place by a nut and washer 18 attached to the lowermost end of the in 14. The roller slides in a cam slot 19 see Figs. 1 and 1") in the cradle top plate 2 so=that as the gun recoils the slide 16 will be moved to the right, the pinion 11 being constrained to revo ve by the fixed rack 13.

The cam slot 19'is so shaped that the gun may recoil approximately two and one-half inches with the breech block in the closed position for the purpose of allowing retraction of the firing pin and also a similar distance with the block fully open for a purpose which will presently. appear. After the block has opened a suflicient distance to have an ejection chamber 20 in the block in position to receive the empty cartridge case, extraction of the case begins and is completed during the initial three inch movement of the block. During the final three inch movement of the block the empty case is carried thereby to the right by means of lugs 21 in the block so that during further recoil of'the gun (the block having completed its opening movement). the base of the cartridge case will be in position to .be struck by an ejector 22 (see Fig. 5) which iscarried by the drum or magazine and which projects into the breech block when open through an aperture 23 to cause the empty case to be pushed forward until it drops from the ejection chamber 20 of the breech block.

The mechanism for producin of the empty cartridge case inc udes an L- shaped extractor 24 (see Figs. 3", and 4) whose foot terminates in a crescentric lip which is normally engaged in the rim of the loaded cartridge. The extractor is mounted in a guide bracket 25 on the left side of the breech ring and is operatiyely connected to an extractor slide 26, (see also Figs. 1', '3,-

y and 5) by means of a lever 27, which fulcrums about a pin 28 screwed to the breech ring adjacent the slide and locked against removal in any suitable manner. One end of the lever is adapted to slide in a trans verse groove in the front end of the extractor to slide in a tr nsverse groove in I the front end of the extractor. slide and the other end is received in a forked projection on the extragtor. (See Fig. 1').

extraction mounted on the left side of the gun is ener- Le ia-4&9

The extractor slide is mounted in a. recess in the upper right side of the breech ring and is retained by means of keys 29 on the inside walls of the recess which overlap corresponding keys 30 on the slide (Fig. 6). The under face of the slide is recessed to receive a spring 31 (see Fig. 5) confined between the rear end of the slide and the frontwall of the slide receiving recess of the breech ring. The slide is moved forwardly against the tension of the spring 31 to cause a resultant rearward motion of the extractor through the instrumentality of a spring pressed plunger 32 mounted in the raised rear end 33 of the slide and working in a cam slot 34 on the upper face of the sliding breech block. The breech ring is provide with an aperture 35 to accommodate the plunger as it is moved-back and forth by the cam slot. During initial lateral movement of the breech block the plunger rides idly in the cam slot and does not reach the inclined portion of the slot until the ejection chamber 20 of the block is in position to receive the empty case. Extraction then commences and. is completed when the plunger arrives at the foremost end of the inclined portion of the slot in which relative posi: tion it is constrained to remain until the lugs 21 during the final movement of the breech block have conveyed the empty case to the right. When the breech block is completely open (the empty case being in position to be ejected) the plunger having arrived at the extreme left end of the cam slot will be During counterrecoil of the barrel andthe closing of the breech block, the plunger will ride up the inclined surface of the left terminus of the cam'slot and across the to of the block until it reenters the right terminus of the slot where it is again in initial position. Y

During the recoil movement of the gun in which the extraction of the empty cartridge case is accomplished the loading mechanism gized7 and released. The loading mechanism consists of a rod 36 (see Figs. 3, 3, 4 and 4), a the front end retained by the bridge support 6 and'its rear end secured in the cradle extension 1. The forward portion of therod is reduced and a urrounded by a coil spring 37, the free end of the spring confined by the head of a hollow rammer 38' reciprocal on the rod and which is formed with splines 39 (see Figs. 3, 4 and 7), at least oneof which extends the greater length thereof to serve as a guide as will hereinafter appear.

Secured to the 'aeket 4 is an annular casing 40 in which 1s securely held a bushing having splines 41 (see Figs. 4 and I) which '45, a retaining pin 46 therefor projecting into a slot '42 in the sleeve to limit independent reciprocal movement of the slide against a cushioning member, specifically a spring 47 which is provided to yieldingly retard the ramm'er as it is swung to ramming position on completion of its rearward stroke.

Attached to or formed on the cradle. extens sion 1 (Figs. 3, 4, 9-and 10) is a rounded plate 48 formed with an endless cam groove (Figs. 1 and 2.), which for convenience will be designated the lower groove 49 and the upper groove 50; When the gun is inbat tery, the roller 45 ispo'sitioned'at the front end of the lower groove 49 (Fig. 9) the loading arm 43 being in outermost or inoperative position. As the gun recoils the splines on the rammer 38 and the bushing in the casing- 40 being in alignment the rammer will be retracted during recoil of the gun to compress the rammer spring 37 and the roller 45 will be moved to the rear in the lower groove 49 until coacting with the grooved camsurface 51 it will ride into the upper groove 50. This movement results in rotating the rammer 38 in'a clockwise direction (looking from the rear) and swings the loading arm 43 to a position in rear of the next cartridge in the magazine. The rotation of the rammer also releases the engaging splines and permits the rainmer to be driven forward by the rammer spring tofeed the cartridge into the breech while the gun is still in the full recoil position. It will be understood that the breech ring and breech block are provided respectively with openings 52 and 52 (see Fig. 4) to permit insertion of the shell and passage of the rammer arm.

It willbe noted from Figures 4 and 4 that when the loading movement is completed the rammer has not yet returned to initial position being restrained by. the rammer arm which has been brought to rest by the ex-' tractor. On counterrecoil the rammer moves forward with the gun until the roller 45 has reached the limit 'of its forward movement, the rannner arm serving to hold the loaded round in position until the breechblockstarts to close. During the continued movement of the gun incounterrecoil the loading arm being-at rest and in the operative position will pass through the openings 52 and 52' in the breech block and breech ring.

The splines on the rammer and'bu shing are maintained in interlocking engagement until the gun has returned to within a short distance of the in battery position and when disengaged the rammer is free to rotate in a counter clockwise direction by reason of the initial torsion placed on the rammer spring in assembly and the roller is returned to its normal position in the forwardpart of the lower groove 49. I

Referring to Figures 5, 6xand 7, a cam shaft 53 is journaled in brackets on the right hand side of the cradle to permit passage thereabove of the slide breech block. A sleeve 54 (see Figs. 5* and 6) mounted on the shaft is retained in an apertured lug 55 on the breech ring so as to be rec-iprocated on the shaft as the gun moves in recoil and counterrecoil. The sleeve is provided with pins 56 disposed in the grooves of the cam shaft for the .purpose of causing the sleeve to be rotated a half turn (clockwise) during recoil. Upon completion of recoil a ratchet wheel 57 on the front end of the sleeve is engaged by a pawl 58 mounted on the lug and serving to lock the sleeve against rotary movement during counterrecoil. Referring to Figure 8 a ratchet wheel 59 (see Figs. 7 and 8) mounted on the front end of the cam shaft is adapted to be held by a pawl 60 on thefront bracket for the purpose of preventing rotation Of the shaft during recoil ofthe gun.

During counterrecoil, the functions of the ratchcts are reversed and the cam shaft is rotated a half turn in a clockwise'direction. This rotation is transmittedto a drix e shaft 01, located underneath the cam shaft (see Figs. 5 and 7), by means of a bevel gear 62 on the front of the cam shaft, a pinion 63 and worm 64 on a vertical shaft 65 and a worm wheel 66 on the front end of the drive shaft.

The ratio of the gearing is such that a half turn of the cam shaft will producee. onetenth turncf the drive shaft, this rotation being transmitted in the same ratio to the magazine (37 by means of sprockets {l8 and a chain (59, whereby the magazine is intermittently rotated during cormterrecoil to successivcly bring each of the ten rounds in the magazine into exact alignment with the bore of the gun and in position to be fed into the bore by the rammer arm.

Rotation of the drive shaft is also transmitted in the same ratio to an indicator disc 70 (Figs. 5 and 6) through bevel gears 71, one of which is yieldingly mounted on the drive shaft and the other connected with the disc and rotatably mounted on an arbor 72 screwed into a trigger housing 73 which is rigid with the cradle.

Disposed in the trigger housing 73 are a 76 by means of a c'rafili 77, journaled in the cradle for the purpose of retracting the tugger rod as the trigger is pressed. The frontfiring rod 78 carries on its forward end a lever 7 9 which with an arm 80 forms a bell crank lever for actuating a pivoted cam plate 81' either to the raised or lower position accordingly as the trigger is pressed or released.

The two rods are constrained to be moved in unison by means of a lug 82 on the free end of a leaf spring 83 secured to the trigger rod74 and normally holding the lug in raised position so'that it'will engage in a slot 8& in the firing rod 78. The lug is formed with a central upstanding extension 85 which projects through and is free to move in an elongated slot -86, which is a continuation of the slot 84.

The indicator disc 70 is provided with a I ramp 87 on its under side which is so located in its normal position with the pointer 88 on zero that the extension 85 on the lug 82 will pass to the left of the ramp and will be maintained in the path thereof when spring 89 surrounding the rod and confined by a nut on the 'front'end of the rod and an annular shoulder in the housing, this forward movement actuating the bell crank lever to lower the cam plate 81 and allow the gun to return to battery without firing the last or tenth round.

The trigger rod is again brought into looking engagement with the firing rod by release of the trigger which is then automatically returned to cocked position through a plunger 90 (Figs. 5 and 6) mountedin the grip'91 and bearing against the lower part of the trigger to rotate the trigger on its axis until the upper part of the trigger is stopped by the rear wall 92 of the pivot slot in the grip. This action results in corresponding forward movement of thetrig er rod until the lug 82 on the leaf sprin is ee to spring up into the slot 84; in the ring rod. When the magazine is replenishedor replaced the gun is ready to go into operation by pressmg the trigger, the cam plate 81 being elevated thereby to actuate the-firing mechanism.

Referring particularly to Figures 2, 10 and 11, the firing mechanism which may be of'conventional structure, is carried by the breech block 10 and includes a hollow firing pin 93 formed with a striker 94 adapted to project through an opening in the breech block. Within the firing pinis a 'slidable 1 spring to engage in a slot 102 in the ing The outer-end of the shaft 99 is provided with an arm 103 adapted to be swung upwardly to rotate the shaft by means of a plunger 104 which in turn is'elevated by the cam plate 81. During initial rotation of the shaft the combined lever 89 drives the inner member 95 forward to compress the spring 96 while continued rotation causes a projection105 on the lever to engage a notch 106 onthe sear to depress-the sear and release the firingpin. i

' When in fired position, the firing pin will be at rest a ainst the front wall of the firing pinrecess 1n the breech block so that the spring will tend to force the inner member 95 to the rear. However, inasmuch as the cocking lever bears against both the firing pin and the inner member and since the leverage between the. inner member and the cockin lever is greater than that between the 'firlng pin and the lever, the resultant force on expansion of the spring will produce rearward movement of both of the members thereby retracting the firing pin to cocked position where it is held by the sear.

The plunger 104, which is mounted on one side at the rear end of the breech ring is provided with a roller 107 for contacting the cam plate 81 and also with an ear 108 on its inner side for compressing a spring 109 disposed in the breech ring and adapted to return the plunger to lowered position so that it need not be actuated by the arm 103 and consume energy from the firing pin spring.

Any suitable device for locking the cock .ing lever in idle position Ina be provided, a

preferred form as herein s own consistin .of a horizontally disposed bolt 110 (Fig. 2

formed with an annular groove for receiving a lug 111 on the shaft 99. As the shaft 99 is:

rotated the .bolt may be freely reciprocated in an aperture 112 in a. vertical bolt 113..

The bolt 113 is provided with ahandle whereby it may be raised and rotated to change the position of its aperture 112 and the handle may be conveniently lodged in a receding slot 115 to hold the vertical bolt in locking position and cut ofi reciprocation of the bolt 110 and rotation of the shaft 99..

. To fire the gun assuming it to be in battery andloadd the trigger 75 is pressed retracting the trigger and firing rod 74 and 78 and elevating t .e cam'plate 81 and plunger 04. The consequent rotation of the shaft 99 

